1. Field of the Invention
The present invention relates to the field of wireless communications, and particularly relates to a method and device for calculating a relative orientation angle as well as a relative positioning method.
2. Description of the Related Art
In general, the relative orientation angle between two mobile devices (e.g., first and second mobile devices) refers to the angle between the device orientation of one of the two mobile devices and the straight-line direction along the straight line from the one mobile device to another.
At present, in the conventional relative orientation angle calculation methods, first it is necessary to obtain the initial coordinates of the two mobile devices and their inertial sensor data on the basis of which the relative positions (coordinates) of the two mobile devices in a moving state are estimated, and then, the relative orientation angle between the two mobile devices may be determined by utilizing a positioning method such as the well-used triangulation approach.
For example, it is possible to carry out node (i.e., a mobile device) positioning and tracking in a network by sending a radio signal between the two mobile devices. However, when sending the radio signal, the two mobile devices may be in a moving state. As such, there may exist the Doppler effect between the two mobile devices. The Doppler effect may result in the change of the propagation distance of the radio signal between the two mobile devices, so that the receipt frequency of the radio signal is not accurate enough. In addition, if a process such as frequency based encoding is conducted by using the radio signal at the sending mobile device, then the Doppler effect may also result in a decoding error of the radio signal at the receipt mobile device.
Since the influence of the Doppler effect exists in various scenarios, in the conventional techniques, a process of compensating for the Doppler effect is conducted as needed in general. For example, the principle of the Doppler effect is usually adopted to compensate for the above-described inaccurate receipt frequency so as to more accurately carry out positioning with respect to a mobile device, so that it is possible to obtain the relevant relative orientation angle.